Transformer for electric-arc cutting and welding apparatus



May l, 1928. 1,668,377

' F. c. OWEN TRANSFORMER FOR ELECTRIC ARC CUTTING AND WELDING APPARATUS Filed Nov. 12. 1925 Patented May 1, 1928.

UNITED STATES`v FREDERICK C. OWEN, 0F FAYETTEVILLE, NORTH CAROLINA.

TRANSFORMER FOR ELECTRIC-ARC CUTTING AND IKT}`l`.|I)I1\l'Glv APPARATUS.

Application led November 12, 1925. Serial No. 68,609.

This invention relates to alternating current electric arc cutting and welding apparatus and more particularly to polyphase transformers for such apparatus.

The invention has for one of its objects to improve and .simplify the general constructin of transformers of the character stated and to provide transformers that shall ,be so wound and constructed as to obviate the necessity of the use of fans or other mechanical cooling means and the use of flux diverters, damping devices or manually operated resistances and react-ances for regulating the current and -potential in the primary and secondary windings.

VVfitli the foregoing and other objects in view, the invention consists of the novel construction, combination and arrangement of parts hereinafter fully described and claimed, and illustrated in the accompanying drawing, wherein: A

Figure 1 is a Ydiagrammatic view of an alternating current elect-ric arc cutting and welding apparatus embodying a transformer constructed in accordance with my invention,

Figure 2 is a similar view illustrating a slightly modified form of the transformer, and

Figures 3, 4 and 5 are similar views illustrating further modified forms of the transformer.

Corresponding andlike parts are referred to in the following description, and designated in all the figures of the drawing, by similar reference characters.

Referring in detail to 4the drawing, and more particularly to Figure 1, 1 designates a core which is of laminated construction and embodies a top leg 2, bottom leg 3, side legs 4, and a middle leg-5. x

The primary winding of the transformer comprises coils 6, 7 and 8 mounted on the legs 4 and 5. The' coils are connected by wires 8 and 9. Leads 10, 11 and 12 connected respectively to the respective coils 6, 7 and 8 extend to the power circuit. rl`he coils of the winding have, as should be apparent, an open delta or Y connectlon.

The secondary winding of the transformer comprises a single coil l()a mounted on the leg 5 and provided with taps 11. One end of the coil 10a is connected by a lead 12 to the work 13 which is to be cut, welded or repaired, and any of the taps 11 may be connected by a lead 14 to the' cutting or welding electrode 15.

In Figure 2 is shown a slightly modified 'form of the transformer. The core and primary winding of this transformer are similar to the corresponding parts of the transformer shown. in Figure 1. The secondary winding is, however, different, and as shown section consisting of an auxiliary or current regulating coil 2O mounted on the leg 5. lliese coils are connected in series, and the coil 20 is provided with taps 21. A lead 12 extends from the coil 20 to the work 13, and any one of the taps 21 is adapted to be connected to the electrode 15 by a lead 14a.

A further modified Vform of the transformer is shown in Figure 3. This transformer embodies a core and primary winding similar to the corresponding parts of the transformer shown in Figures 1 and 2. The secondary' winding of this transformer differs from the corresponding parts of said other transformers, and comprises a section consisting of main or volt-age regulating coils 22 and 23 mounted on the legs 2 and 3 at one side of the leg 5, a'section consisting of main or voltage regulating coils'24 and 25 mounted lon the legs 2 and 3 atr the opposite side of the leg 5, and a section consisting of an auxiliary or current regulating coil 26 mounted on the leg l5. The respective scctions of thev main or voltage regulating coils 22-25 are connected in parallel, and there sections are connected in series with the auxiliary or current regulating coil 26. The coils are connected by a lead 12b to the work 13. The coil l26 is provided with taps 27 any one of which is adapted to be connected to the electrode 15 by a lead'll.

The transformer shown in Figure 4 differs from those previously described in that it has two independent Secondary windings each of which consists of coils 28, 29 and 30 mounted on the legs 2, 3 and 4 at opposite sides of the le 5. Any one or two of the coils of each o these windings may be used as a main or voltage regulating coil or coils, and such coil or coils will be connected to the work. The remaining coil or coils of each of these windingswill constitute the auxiliary or current regulatingcoil or 'coils and will be provided with taps '30a-any one of which may be connected to the electrode.

The coils of each of these windings are con.- nected in series.

A further modified form of the transformer is vshown in Figure 5. This trans/-v former is adapted to permit two cutting,l Welding or repair operations 'to be performed at the same time. Its core and primary winding are similar to the corresponding. parts of the other transformers. 'The secondary of this transformer differs from the corresponding parts of the other transformers, and comprises two windings each embodying a main or voltage regulating coil 31 and an auxiliary or current regulating coil 32. The coils-31 are mounted on the leg 3 at opposite sides of the leg 5 and the coils 32 on the leg 2 at .opposite `sides of the legl 5. 'Ihe coils of each winding are connected in series, and each coil 32 is provided with taps 33, each coil 31 is connected to the Work 13 by a lead 122, and any one of the taps 33 is adapted to be connected to the electrode l5 by a lead 14. If desired the secondary windings of this transformer may be connected in parallel or series to Vadapt the apparatus for performing a single cutting, welding or repair operation.

In each transformer, the core provides a plurality of completely closed magnetic paths, the primary Winding has a section distributed about a portion of each of said paths and a section distributed about both of said paths, and the secondary winding is distributed about both of said paths.

When current iows through the primary Winding, a constant main voltage and a variable secondary voltage Will be induced in the secondary winding. The reaction between these voltages is such that there is induced, in the secondary circuit including the Work and electrode, a light current at light load and a heavy current at heavy load, with the result that a stable arc of high power factor maybe readily main-r tained during overhead, vertical and horizontal cutting, Welding or repairing of steel, Wrought iron, cast iron, malleable iron, aluminum, brass, bronze, copper and alloy metals. Furthermore, the arc is free from sputtering and spitting, and it has been found that askilled operator can maintain an arc within one and one-half per cent plus or minus of the rated capacity of the tap with which the electrode is connected.

What is claimed is:

1. A transformer comprising a. core providing a plurality of closed magnetic paths,

a primary Winding embodying sections distributed around aportion of eachof said paths and a section distributed around both of said paths, said sections having an open delta or Y connection and a secondary windinghdistributed around a plurality of said pat s.

2.'A transformer comprising a core providing a plurality of closed magnetic paths, a primary Winding embodying sections distributed around a portion of each of said paths and a section distributed around both of said paths, said sections having an open delta or Y connection and a secondary winding embodying coils distributed around different portions of said paths.

3. A transformer comprising a core having top, bottom, side and middle legs, a primary winding comprising sections distributed about the side and middle legs and having an open delta or Y connection, and a secondary Winding distributed around the middle leg.

4. A transformer comprising a core having top, bottom, side and middle legs, a primary winding comprising sections distributed about the vside and middle legs, and a seconda-ry Winding having coils distributed about the top and bottom legs at opposite sides of the middle leg.

5. A ,transformer comprising a core having top, bottom, side and middle legs, a primary Winding comprising sections distributed about the side and middle legs, and a secondary winding distributed aro-und the top, bottom and middle legs.

6. A transformer comprising a core having top, bottom, side and middle legs, a primary Winding comprising sections distributed about the side and middle legs, and a secondary Winding embodying coils distributed around the top and bottom legs and connected in parallel and a coil distributed around the middle legand connected in series with said other coils.

7 A transformer'. comprising a core having top, bottom, side and middle legs, a primary winding comprising sections distributed about the side and middle legs only, and a secondary Winding having a portion thereof arranged on the core in close association with the primary Winding and a portion thereof arranged on the core remote from the primary Winding.- 8. A transformer comprising a core having top, bottom, side and middle legs, a primarywinding having connected sections on the side and middle legs, and a secondary `Winding having coils on the top and bottom legs.

In testimonywhereof I affix' my signature.

FREDERICK C. OWEN. 

